Wide range power control for electric discharge lamp and press using the same
First Claim
1. In a printing press for printing electromagnetic radiation curable printed matter on sheet material and an arc discharge lamp for emitting electromagnetic radiation to effect curing of the printed matter, apparatus for controlling the energization of said lamp comprising:
- a transformer having a primary winding and a secondary winding;
means for connecting said secondary winding to said lamp;
A.c. power supply control means for connecting said primary winding to A.C. power supply lines for supplying A.C. voltage to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires to emit electromagnetic radiation and controlling the level of A.C. power supplied to said lamp from said A.C. power supply lines, said control means being responsive to a control signal for varying the amount of power supplied to said lamp in dependence upon the value of said control signal;
feedback means for providing said control signal and including detection means for detecting the amount of power supplied to said lamp to provide an output signal, and means for comparing said output signal with a reference signal indicative of desired lamp output intensity and providing said control signal having a value in dependence upon any difference therebetween; and
,said feedback means also including means for further varying said control signal so as to have a value dependent upon the speed of said printing press so that the intensity of radiation emitted by said lamp varies in dependence upon the speed of said printing press.
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Accused Products
Abstract
A mercury vapor electric discharge lamp is supplied with AC electric power, which is variable over a wide range, to control the lamp output power in the form of the intensity of the electromagnetic radiation emitted over a correspondingly wide range of from approximately 5% to 100% or better of rated output power without lamp extinction. An AC phase modulation control circuit controls the AC electric power supplied to the lamp such that applied voltage remains relatively constant while the current is controllably varied determined by the phase angle of conduction in the control circuit. Control of the AC phase modulation control circuit is effected in response to the actual output power of the electromagnetic radiation emitted by the lamp, the speed of a printing press or conveyor line with which the lamp may be used to cure ultraviolet sensitive inks, paints, plastics and the like on some form of substrate. Moreover, the actual lamp intensity, when below a called for intensity, may be used to control the speed of the press conveyor, process line and the like. Means also are disclosed to indicate, for example, lamp aging, press or process slow down and the like, and a lamp cooling blower is automatically controlled to vary the amount of cooling proportional to lamp output power.
67 Citations
7 Claims
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1. In a printing press for printing electromagnetic radiation curable printed matter on sheet material and an arc discharge lamp for emitting electromagnetic radiation to effect curing of the printed matter, apparatus for controlling the energization of said lamp comprising:
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a transformer having a primary winding and a secondary winding; means for connecting said secondary winding to said lamp; A.c. power supply control means for connecting said primary winding to A.C. power supply lines for supplying A.C. voltage to said lamp through said transformer of sufficient amplitude to ionize the gas in said lamp so that said lamp fires to emit electromagnetic radiation and controlling the level of A.C. power supplied to said lamp from said A.C. power supply lines, said control means being responsive to a control signal for varying the amount of power supplied to said lamp in dependence upon the value of said control signal; feedback means for providing said control signal and including detection means for detecting the amount of power supplied to said lamp to provide an output signal, and means for comparing said output signal with a reference signal indicative of desired lamp output intensity and providing said control signal having a value in dependence upon any difference therebetween; and
,said feedback means also including means for further varying said control signal so as to have a value dependent upon the speed of said printing press so that the intensity of radiation emitted by said lamp varies in dependence upon the speed of said printing press. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification